I was talking about biohacking and such in the car with my dad yesterday, and we were talking about blinkies, and specifically ones that could keep glowing like an xglo, but without the radiation. Thinking about that, would it be possible to make something that is just a coil, small capacitor, and a led, so you could just recharge it with a phone and it would last for a bit? Wouldn’t have to be all day power or anything just for 20 minutes or so. Another idea would be using the temperature gradient from outside your body to the inside. would there be enough of a difference from just under the skin to say the other side of a flex? Just thinking out loud here, to see if any of this sounds remotely feasible.
@satur9 would be a good person to ask about capacitors and phone power I think.
The problem with thermal gradients is that you need a thermal gradient, so ideally you would have a heatsink on the outside of the body… But at that point you might as well put the entire blinkie on the outside and then you don’t have any of the issues inside that you are trying to solve.
There may be fractions of a degree difference in temperature on opposite sides of a flex implant, primarily caused by the break the implant creates in the capillaries that delivery blood to that area of the skin. That would only equate to millivolts and microamps from even the most efficient thermopile or peltier. Your body is very good at thermoregulation, so from an energy harvesting perspective I think subdermals are just not viable. Only transdermals like Zwack said.
If you want to have capacitors storing energy in an implant then check out this post for relevant calculations